Or worse yet they fasted for a short period with an "open mind"--a very dangerous state in which to approach anything new. I have found through considerable experience with people professing to have open minds that the expression "I'm open minded" usually means that someone has already made up their mind and new data just passes straight through their open mind--in one ear and out the other. Or sometimes, the phrase "open mind" means a person that does not believe any information has reality and is entirely unable to make up their mind. The most commonly leveled criticism of fasting is that in its efforts to survive self-imposed starvation the body metabolizes vital tissue, not just fat, and therefore, fasting is damaging, potentially fatally damaging. People who tell you this will also tell you that fasters have destroyed their heart muscle or ruined their nervous system permanently. But this kind of damage happen only when a person starves to death or starves to a point very close to death, not when someone fasts. There is a huge difference between fasting and starvation. Someone starving is usually eating, but eating poorly and inadequately, eating scraps of whatever is available such as sugar, white flour, rancid grease, shoe leather, or even dirt. Frequently a starving person is forced to exercise a great deal as they struggle to survive and additionally is highly apprehensive. Or someone starving to death is confined to a small space, may become severely dehydrated too and is in terror. Fear is very damaging to the digestive process, and to the body in general; fear speeds up the destruction of vital tissue. People starve when trekking vast distances through wastelands without food to eat, they starved in concentration camps, buried in mind disasters, they starve during famines and starve while being tortured in prisons. Until water fasting goes on past the point where all fatty tissues and all abnormal deposits have been burned for fuel and recycled for the nutritional elements they contain, vital muscle tissues and organs are not consumed. And as long as the body contains sufficient nutritional reserves, vital organs and essential tissues are rebuilt and maintained. In fact the body has a great deal of intelligence that we don't give it credit for. It knows exactly which cells are essential to survival, which ones are not. The body knows which cells are abnormal deposits, and it goes to work to metabolize them first. For example, the body recognizes arthritic deposits, cysts, fibroids, and tumors as offensive parts of the landscape, and obligingly uses them for foods in preference to anything else. A starving (not fasting) body also knows precisely in what order of priority body cells should be metabolized to minimize risk of death or permanent disability.